virtio-scsi: do not use vring in dataplane

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 9 insertions, 43 deletions

diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 5b29bac..0c30d2e 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -23,7 +23,6 @@
 #include <block/scsi.h>
 #include <hw/virtio/virtio-bus.h>
 #include "hw/virtio/virtio-access.h"
-#include "migration/migration.h"
 
 static inline int virtio_scsi_get_lun(uint8_t *lun)
 {
@@ -43,7 +42,8 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
 
 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
 {
-    const size_t zero_skip = offsetof(VirtIOSCSIReq, vring);
+    const size_t zero_skip =
+        offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
 
     req->vq = vq;
     req->dev = s;
@@ -66,11 +66,10 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 
     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
-    if (req->vring) {
-        assert(req->vq == NULL);
-        virtio_scsi_vring_push_notify(req);
+    virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
+    if (s->dataplane_started) {
+        virtio_scsi_dataplane_notify(vdev, req);
     } else {
-        virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
         virtio_notify(vdev, vq);
     }
 
@@ -417,7 +416,7 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
     VirtIOSCSIReq *req;
 
-    if (s->ctx && !s->dataplane_disabled) {
+    if (s->ctx && !s->dataplane_started) {
         virtio_scsi_dataplane_start(s);
         return;
     }
@@ -567,7 +566,7 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
     VirtIOSCSIReq *req, *next;
     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 
-    if (s->ctx && !s->dataplane_disabled) {
+    if (s->ctx && !s->dataplane_started) {
         virtio_scsi_dataplane_start(s);
         return;
     }
@@ -687,11 +686,7 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
         aio_context_acquire(s->ctx);
     }
 
-    if (s->dataplane_started) {
-        req = virtio_scsi_pop_req_vring(s, s->event_vring);
-    } else {
-        req = virtio_scsi_pop_req(s, vs->event_vq);
-    }
+    req = virtio_scsi_pop_req(s, vs->event_vq);
     if (!req) {
         s->events_dropped = true;
         goto out;
@@ -733,7 +728,7 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 
-    if (s->ctx && !s->dataplane_disabled) {
+    if (s->ctx && !s->dataplane_started) {
         virtio_scsi_dataplane_start(s);
         return;
     }
@@ -901,31 +896,6 @@ void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
     }
 }
 
-/* Disable dataplane thread during live migration since it does not
- * update the dirty memory bitmap yet.
- */
-static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
-{
-    VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
-                                 migration_state_notifier);
-    MigrationState *mig = data;
-
-    if (migration_in_setup(mig)) {
-        if (!s->dataplane_started) {
-            return;
-        }
-        virtio_scsi_dataplane_stop(s);
-        s->dataplane_disabled = true;
-    } else if (migration_has_finished(mig) ||
-               migration_has_failed(mig)) {
-        if (s->dataplane_started) {
-            return;
-        }
-        blk_drain_all(); /* complete in-flight non-dataplane requests */
-        s->dataplane_disabled = false;
-    }
-}
-
 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -956,8 +926,6 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 
     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
                     virtio_scsi_save, virtio_scsi_load, s);
-    s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
-    add_migration_state_change_notifier(&s->migration_state_notifier);
 
     error_setg(&s->blocker, "block device is in use by data plane");
 
@@ -991,8 +959,6 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
     error_free(s->blocker);
 
     unregister_savevm(dev, "virtio-scsi", s);
-    remove_migration_state_change_notifier(&s->migration_state_notifier);
-
     virtio_scsi_common_unrealize(dev, errp);
 }